The invention is directed to a plug-in connection for electrical interrogation or retrieval of data from a mileage counter of a wheel revolution counter type by means of a device serving to accept the data of a wheel revolution counter, wherein the wheel revolution counter is equipped with a substantially cylindrical housing, a revolution storage and at least a counter storage, and means for overhung fastening of the wheel revolution counter are provided at one end of the housing.
If the distances traveled by motor vehicles, trailers and semi-trailers are to be detected in an extensively tamper-proof manner, e.g. because these vehicles will be taxed according to the mileage, it is conventional to use so-called wheel revolution counters as mileage counters. These wheel revolution counters are attached directly to the axle cap or the wheel hub of the respective vehicles and accordingly require neither flexible shafts nor electrical cables for the transmission of the measured values. Since mileage counters of this type revolve with the vehicle wheel to which they are assigned, it is necessary to provide a comparison speed of zero for the counting process, which is usually effected by means of a pendulum.
In general, wheel revolution counters are constructed as printing wheel-revolution counters, since a record of the data removal and accordingly a printing of a record is required in the event that the mileage is taxed. Of course, it can also be advisable to produce such a printed record for checking maintenance intervals, for monitoring wear, for producing shipping calculations or for determining the distance travelled of rented vehicles.
In order to be able to assign the current mileage reading to the respective vehicle, it is required, in addition, to print out a device or identification number, i.e. a fixed set of number type which can be appointed to a vehicle prior to the installation of the wheel revolution counter must be provided in addition to a print wheel set which is driveable as a function of the mileage.
Accordingly, in contrast to wheel revolution counters which display exclusively, considerably more construction space is required in the case of a printing wheel-revolution counter. In the case of wheel revolution counters which are also conceived for use in passenger cars, this space requirement leads to considerable problems with respect to manufacturing and assembly due to the required extreme packing density. This packing density is brought about by the efforts to achieve a suitably adapted aesthetic structural form having a housing diameter of approximately 50 mm and an overall height which should not exceed, or should exceed only slightly, the side contours of the vehicle, in view of the risk of collision.
Moreover, in printing wheel-revolution counters, there is the problem that the access to the insertion slot for the printed record must be opened for a print out and accordingly there is a risk of penetration of dirt and corrosion in addition to the risk of tampering. In any event, a hermetic sealing of the wheel revolution counter, which would be desirable for severe use conditions, is not possible. Such a device requires a high degree of subjective care during the removal of data as well as when being subsequently closed so as to be at least tight against moisture.
Given this situation, a wheel revolution counter which can be electrically interrogated would offer advantages, especially since recently the functioning of electrical components in the given temperature range is ensured and technical means for securing the data transmission are known.